1. Field of the Invention
The invention concerns apparatus for recognizing code marks.
2. Description of the Related Art
When controlling automated conveying or sorting processes, a problem is encountered in that individual articles conveyed on tracks that branch off must turn off at some forks but not at others. The choice of tracks and control of the switch-points at appropriate forks may take place from a central location by using a computer to monitor the path of an individual container and by corresponding actuating the particular switch-point. However, a plurality of control lines must be installed for such a purpose, whereby the cost and also the susceptibility to interference of the entire system become unacceptably high.
It is known to code mark the articles to be conveyed so that they contain data arrays providing data relating to a specific path. The code marks to that end are arrayed in discretely set, mutually relative positions. To read and then control the switch-point at each fork, read stations are mounted in front of these forks and include a specific number of code readers. The distance between the code readers is determined by the distance between the code marks. This known apparatus provides a separate code reader for every possible position of a code mark. Therefore, the number of code readers must correspond to the number of possible code mark positions, and the read station consequently is extraordinarily costly. Furthermore, the wiring together of the individual code readers is highly elaborate and further increases the cost of installation. Lastly the known apparatus suffers from a substantial problem in that all code readers must be precisely adjusted, i.e. they must be electrically matched to assure problem free operation. It is clear that such complex read stations entail high costs.